V" •Mi' 

Copy 1 



li Will m \\m FiiD. 



A TREATISE ON 



Hammering I Straightening 



SAWS 



SHOWING THE 



Latest Improved Methods, 



ILLUSTRATED 



•BY- 



J. H. MINER, Baton Rouge, La 



BATON ROUGE : 

CAPITOLIAN-ADVOCATK BOOK AND JOB PRINT, 

1887. 



™ sif lEE m mm Fii. 



A TREATISE ON 



Hammering i Straightening 

CltCUILAl AlB LOMI^ 

iSAAA^S 



SHOWma THE 



Latest Improved Methods. 

ILLUSTRATED 

J. H. MIXER, Bato:&^ Eouge, La. 

L NOV 1 1887J/ ^ 

BATON ROUGE : 

CAPITOLIAN-ADVOCATE BOOK AND JOB PRINT, 

1887. 



HAMMERING SAWS. 



PREFACE. 

In tliis advanced day of improved machiuery and competition, s^ 
strong among mill men. It lias become an item of the utmost impor- 
tance to produce good true lumber in greater quantity and quality. 
This can only be done by employing tbe best Sawyers and Filers, men 
who can hammer their saws and keep them in tbe best of running 
order. These men always command from $3,50 to $6.00 per day and 
are never out of employment, because such men are cheap at a high 
price. The expense and delay of a mill in sending saws to the saw- 
maker are items of great expense and besides no saw is ever sent off to 
be hammered until it has spoiled its worth in making bad lumber, 
where if tbe saw was hammered iii the mill this expense and delay 
would be avoided. This is the intention of this book, to enable Sawyers 
and Filers to hammer their own saw s. There are but few who claim 
to hammer a saw, that can keep a saw in good condition and to run 
as Avell as new until worn out, because they work from no theory, 
not having had the prober instruction. There are many saw hammerers 
of 25 years experience, that cannot properly adjust a saw, following 
the fogy way and not taking hold of improvements. These men served 
a time to learo the trade and then did not learn it. While now a man 
can learn quickly and in the mill where he can watch the results. 
This book being gotten up tha*; a man may soon learn without the loss 
of time and expensive tools, which puts it into the hands of all who 
wish to learn the art. The instructions are so simplified that it is 
impossible for a man of average intelligence not to learn if he will 
only study it well, beginning at the first and studying each part 
thoroughly before working on the saw. It is not expected that a man 
is to learn every part of a trade at once. If he does he soon learns 
nothing. I expect that every one that receives this book intends to 
try and learn it, which I guarantee he will if he tries to, and af^er I 
correspond with him and explain what part he cannot understand 
and then he should not learn on the receipt of this book, I will cheer- 



[i] 



fully refund his money. It beino; understood that he is to give full 
explanation of the work he has done on the saw, the size of it, gauge, 
speed, and t^'hether mandrel heats or not. The indorsements I have 
from the best saw-makers aud millmen are sufficient to convince the 
skeptic that while my ideas are new to many, a trial by my method 
will silence them, and while I do not claim to know it all I do claim 
to have set aside all the fogy ideas that a man may study his life time 
and not master the saw. Think of the great change that of late years 
has taken place in the saw. They are run at twice the speed and 
-much thinner, cutting ten times as much lumber. Certainly this 
great change could not have taken place in the saw without- new 
theory and improvements being brought about in the haoQineringof it. 
Any part of this book that may not be fully understood will be cheer- 
fully explained by writing me in full. Read the conclusion on last 

page. 

J. H. MINER. 



PART 1. 




FIGUE^E I. 

The tools necessary for a man to begin with are very 
few, consisting of anvil, a ronnd and long pien hammer, 
two straight edges IG and 24 inches long. If these tools can- 
not be had conveniently, a good smooth-faced black- 
smiths anvil and hammer will do, a good steel square can 
also be substituted, care must be exercised to apply it 
straight, that is square on the saw. The rig for handling 
and hanging the saw on is shown in Fuj. I. This is in- 
tended where a man is to keep up his saws in the mill, it 
being handy and costs not over $2.50 and will suit a new 
beginner just as well as a $40.00 outfit. To construct this 



[6] 



bench A represents a piece of timber, say 12x12 inches 
set on end and a little higher than half the diameter 
of your largest saw. This block must set in a very solid 
steady place and braced as shown in cut. Near the top of A 
at H is a collar bolt 1 inch in diameter, 19 inches long, 
7 inches from one end is fsatened the collar, the other goes 
through A at the top and must be screwed up very tight. 
The 7 inch end is for the collar. This can be made of hard 
dry wood, and is made as shoAvn at C and F. It should 
be 4 inches in diameter, 5 inches long with an inch hole 
through the center, so as to revolve on the 7 incli projection 
of bolt. At C the block is shown to be reduced to two 
inches, this being the exact size of the eye of the saw and 
made to receive it. This reduced part being 2 inches long 
and two inches in diameter. F shows a round block, two 
inches thick, with a two inch hole in it to receive the end 
of C, These blocks should be square on the edge, not 
bevelled. This will make you just as good a collar 
if you had paid a shop $15.00 for it. The end of 
the bolt to receive this collar is threaded to receive two 
jam nuts, so that when the saw is revolved the nuts will 
not unscrew. K represents a top view, A showing end 
of block. Screws JJ-I) «re applied for springing the saw 
to tind the defects. This being the safeguard for the new 
beginner as well as the experienced. This bench can be 
made in a frame to be moved about if desired. It should 
\)Q set so as to get the best light in front of the operator, 
so that the defects can be seen under the straight edge. 
Where a man runs a small saw at moderate speed he can 
dispense with this bench for a while, until he can build one, 
by standing the saw against a post to test it. All being 
ready the saw is huug on the bench, as shown in Fig. J with 
the full side out, next to you as in cut, then set up screws 
D'D against saw until it appears straight to the eye. 
Your saw may be dished very little, nearly all saws which 



[7] 

need hammering are dished more or less from the log. 
When you have sprung the saw straight with screws. 
The straight edge is applied perpendicularly, as in cut, with 
the left hand while saw is turned with the right watch- 
ing closely and marking all the lumps or high places you 
find, if your saw was sprung or dished it will show 
a little high place outside of the collar when the 
straight edge is applied. This high place extends nearly 
always around the saw and should be marked very plainly, 
a piece of chalk or hard bar soap will do for marking the 
saw. This shows that the dished saw is sprung near the 
collar. Should the saw not be sprung straight and allowed 
to remain dished as in Fig. I^ this high place would 
appear midway between center and rim, as the straight 
edge shows it in cat, in fact it would show the saw spring 
all over, where it really was sprung just outside of the 
collar, which was found by using screws D-D to spring 
the saw in the proper position. So it can be easily seen 
this great advantage of these screws. Should the saAv 1 e 
marked where the lumps appear, while dished, the saw 
would be hammered in every place, except the right place 
and this is why so many fail in attempting to learn the art 
of hammering saws they do not have the right principles 
to start on. In going around the saw with the straight 
edge you sometimes will find one or more very light lumps, 
sometimes there will be three as shown at 1^ 2 and S 
in ¥i(j. II. 



[SI 




FIGMJI^E II. 

These lumps are often blue spots as is often seen on a 
saw, caused from getting too hot in the center and the saw 
to get relief from the great amount of expansion, blisters 
by raising in a high lump. These lumps require several 
marks on them as shown. After you have gone around 
the saAv with the straight edge, as in Fig. I^ marking a 
cross mark on each lump, then take the straight 
edge and apply it in a horrizontal position on the saw, 
which is exactly across the former way, apply it on every 
lump you have marked and you will find some of them that 
will not show a lump this way and where you find that the 
lump shows one way of the straight edge and not the 
other, rub out the cross mark and make a straight mark in 
line with the line that shows the saw to be the straightest 



[9] 

and where the lump appears both ways mark as described, 
a cross mark. The blue spots always expand in a circle 
and shows a high lump both ways of the straight edge. 
After you have marked all the lumps you can find your 
saw will appear about as in Fig. 11^ and shows most of 
the long marks near the rim. These places are sprung 
only one way and are a twist in the saw. The straight 
uniform dotted lines in Fig. 11, shows the straight way 
of the saw, the long marks all in a line with this straight 
dotted line. You now have your saw laid off and ready 
for hammering, that is straightening as it is to be done on 
a wooden block. In Fig. J, the upright square piece A 
will answer the purpose, it should be one-sixteenth of an 
inch higher in the center and the face of the block very 
smooth and uniform. Now lay your saw on the block and 
with your hammer strike a light blow with the round pien 
on the cross marks and use the long jjien on the long 
marks and never across them. The high places will require 
heavier blows, it being safer when striking near the collar 
to strike lightly and two or three blows in one place. The 
places like 2, 2 ^^^ S in ^^8'- ^^i will require several 
blows, say half dozen. Xow great care and judgment 
must be exercised not to strike too heavily. Eaise the 
hammer, if of 3 lbs. weight, VI or 14 inches high and allow 
its weight to fall on the mark, but this is found out by 
practice, thin saws require much lighter blows than a six- 
gauge. After you have gone around the saw, on the block 
with the hammer, stand it on edge on the floor and 
notice if it yet appears full on this side, if so lay it back 
on the block and strike another blow on each mark, and a 
little heavier on the blue si)Ots. It will probably appear 
straight on this side or may dish a little the other way, 
which is all right if it does. Turn the saw around, the other 
side out and hang it on the bench again, not disturbing 
screws D-D and leave the marks you have made on the 



[10] 



other side. Take the straight edge and go around the saw 
on this side, the same as the other, marking all the long 
marks you find, by applying the straight edge at right 
angles on the lumps. After you have marked all the 
lumps, examine and see if any of the marks on this side 
are opposite any of those on the other side, if so you have 
hit too heavy a blow and have raised a lamp on the other 
side. This is the surest way to learn the right kind of a 
blow, always leaving the marks on the side operated on 
with the hammer, until you have the other side laid off and 
examined, then you can rub them out. Nine-teuths of the 
saw-hammerers strike too heavily and if they ever get a saw 
to run they have to do ten times as much work as is necess- 
ary and by this time a man is getting so sick of the job that 
he can't exercise much judgment and quits with a saw 
very little better than at first. Eemember this, it takes very 
few blows to improve a saw, when put in the right place 
and not too heavy. The screws D-D will always show 
Avhere the saw is sprung. Proceed on both sides of your 
saw, say three times on each side, if your saw was badly 
buckled and leave your saw leaning a trifie toward the log. 
Eemember, in the last operation that the blows should be 
much lighter as the lumps are not so high ; do not try to 
get it perfect at first. You probably will not have the 
time and should you work on a saw half a day all would 
expect a perfect saw, and besides a man at such work 
should not do too much at once, until thoroughly familiar 
with the business. Straighten your saw up a little, two 
or three different times, and you can watch the change 
in the saw. Before working on your saw, should it 
be necessary for the saw to run warm in the center 
to work, it will be necessary to treat the saw as 
described in Fig. Ill, before straightening it. The saw in 
this condition will sometimes appear in a kind of a twist 
and cannot be straightened on the block, but on the anvil, 
as described, which is giving the saw some tension before 
straightening it.. 



[11] 

PART 3. 

TENSIONING A STIFF SAW TO PROPER SPEED. 




FIGMJR^E III. 

By tlie time you have your saw straight it may require 
teDsioniug, that is it may be too stiff in the center. This 
saw when runninfi: will snake and heat on the rim, the least 
heat on the rim causing it to form a complete 
twist or wind and unless the saw runs out of the 
timber sufficient to heat the center, there is no running it 
at all. This saw is too loose on the rim and too tight in the 
center, caused by gumming, heat and the action of centri- 
fugal force, all these act on the rim and stretch it, and 
unless the center is stretched to compensate this, the saw 
cannot be run at all. By studying this well and watching 
results closely you will soon understand. Fig. Ill 



[12] 



shows how the saw shoukl be laid off for hammering. 
First strike off three or four lines between the center and 
the rim, keeping nearest the center — these lines can be 
struck on a perfect circle, Avhen the saw is on the bench, 
by holding a piece of chalk steadily against the saw and re- 
volving it. Lay off marks, say 3 inches apart, on these 
circular lines i, 2 and S show where the blue spots were 
and near these no mark for the hammer should be made, 
is now to be opened on the anvil and these blue spots are 
already an open place, caused by heat, all saws do not 
have these blue spots, as described in ¥Uj. 11-^ some- 
times a saw will have one and not often three. The saw 
is now laid off', as in Fig, III, laid on the anvil and 
struck a solid blow with the round pien. These blows 
must be very light and the saw rest solidly on the anvil or 
you will get into trouble. The saw will be sprung instead 
of being opened or stretched at each blow. Eemember 
you are not often straightening the saw, this is only done 
on the block, you want to open the saw and if all your 
blows are perfectly solid and of the same heft, your saw 
will be sprung but very little. The safest way is to taj) 
the saw lightly until you get it firm, then apply the blow. 
Why I caution so against heavy blows, is that this is the 
cause of so many men not learning anything ; they actually 
strike a saw as if they were strikijig in a shop. Having 
gone around this side on three lines, you want to apply 
the same blows on the other side, exactly opposite tbese 
and if your saw is bright, not rusty by turning the saw 
and catching the light you can see an impression, a dull 
spot, and by marking these you have the blows applied 
exactly opposite each other. On this side it is not neces- 
sary to strike quite so heaviiy, but the saw must lay firmly 
on the anvil. Should the imi)ressions not show, it will be 
necessary to measure, strike the same lines exactly oppo- 
site and apply the blows as nearly* opposite as possible and 
you will have less straightening up to do on the block. 



[13] 

These 3 lines may Dot be sufficient to open the saw proper- 
ly and you will have to be governed by your speed and 
size of saw and thickness. If you are running a medium 
.size saw at a moderate speed you will require to have your 
saw not so open as a larger saw of higher speed, the 
medium speed requires that the saw be a little loose in the 
center, which is determined by standing the saw on edge 
on the iioor, taking hold of the top and giving it a shake 
if the center shakes more than the rim the saw is open 
about right. Should the center appear yet stiff, not mov- 
ing when shaken, it will be necessary to lay oft" two more 
lines between the three in Fig. Ill, omitting the blue spots 
and hammering as before on both sides, by watching you 
can soon get the idea of it. Sometimes in large saws the 
center will vibrate and the rim also, this ought not to be 
and the best saw in the world, in this condition will not 
run, new saws are sometimes in this condition and it is 
caused by the saw being opened too near the eye and the 
part on the third line, toward the rim, is too stiff and 
requires hammering, this is in the part of the saw that 
hammering will not open the saw much to speed and any 
saw that appears stiff', in this way, should be opened with 
the hammer on the anvil, and by watching the saw, as it is 
shaken this tight place can be located and bearing in mind 
that this is found when the center and rim both vibrate 
from the shake of the hand. The high speeded saw should 
dish in the center alike both ways and the rim remain 
steady or nearly so. This tight place is found only in high 
speeded saws, and not in the lower speed. In opening a 
saw in the center it should not be hammered nearer the 
center than say 6 to 10 inches, according to the size of the 
saw. Always straighten the saw up on the block, after 
opening, before putting it on the mandrel for work. Use 
precaution and do not do too much at once ; a few blows 
in the right place helps a saw wonderfully and when proper 
work is done on a saw it requires as fine observation as 
the finest part of a watcfc. 



[14] 

PART 4. 



A SAW TENSIONED TOO HIGH FOR SPEED TO OPEN CENTER, 
BEING TOO STIFF ON RIM. 




FI&UR.E IV. 

vSbould } ou get your saw to open in the center, it will 
have to be hammered ou the lim, as in Fig. IV. This saw 
will incline out of the log and heat in the center, it being 
a difficult matter to get it to run into the log and when you 
do, it wi41 run in as badly as it runs out, the saw being too 
open in center for speed to straighten it, so it runs first 
one way then the other, generally out. Lay off one circu- 
lar line around the saw, 4 inches from the rim, as in Figure 
4, and opposite each tooth, make a maik, take the saw to 
the anvil and strike a light blow on each mark, lighter 



[15] 

thau what you did in the center, there being a larger circle, 
requires very light blows, hammer the saw on both sides, 
laying it so as to get the blows opposite each other. One 
line will be sufficient, unless the saw is very open and then 
it may require but very few blows, using precaution, as it 
is much easier to do too much hammering here than in the 
center. Saws that accidentally becoming dished when 
straightened up will be too open, that is if the saw was of 
the. proper opening before, nearly all saw hammerers 
hammer this kind of a dished saw on the anvil, stretch iug 
the saw more all the time, then they have five times 
more work to do on the rim than if they had straightened 
it on the block. By watching closely you will see what is 
needed, resting assured that if you follow these instruc- 
tions closely, you will soon master the saw. In all .cases, 
after hammering on the anvil, the saw should be straight- 
ened upon the block. Eemember that hammering a saw 
is not straightening it. Hammering applies to uniform 
work on the anvil. Straightening is treating the lump on 
the block. 



1 


[16J 

PART 5. 

SHOWING A TWISTED SAW. 




log 
tur 
tha 
wh 
oth 
mei 
ble 
app 
stif 
Fig 


i^y^ ' Xv --------- -1 


1 
1 

or 
' is 
een 
de, 
tke 
im- 
ssi- 
vill 
' is 

in 
fced 






FIGURE V. 

Saws become twisted through accident, by a cant 
, falling on it or jamming the saw. When the saw 
ned around on the bench and watched, it will be s 
t it has a "wind in it and will appear full on one si 
en turning it half way round it will appear full on 
er side. Sometimes saws are run so long without h{ 
ring that tliey get so long on the rim that it is impo 

for the saw to stand straight; the saw ^ 
)ear very stiff in the center, and where a twi.^;ted saw 
f in the center it is necessary to open the center, as 
. J7J, laying oft' not less than 6 lines to be opera 


1 



[17] 

on. HaiJimer the saw on both sides, and should it 
appear yet stiff, operate again on 3 lines, until 
you get the center a little open, and when you do this you 
will often find your twisted saw nearly straight. Then 
take the straight edge and examine the saw all over and 
you will find places on the rim, high one way and with the 
straight edge applied across the high place will show a 
low place or light under the straight edge. The long 
straight dotted lines, in cut, represents the straight edge, 
applied the straight way, as described in Fig. TI, and 
where these twisted places appear higher at the rim, when 
the straight edge is applied, the high way, as shown by the 
long white lines, the saw requires much more hammering 
on the rim at these places, reducing to a conical shape, as 
shown in cut. Twisted saws are nearly always sprung more 
on the rim than any where else, sometimes a little at the 
center. The long pien is used exclusively to remove twists 
and buckles, that is at all places that appear straight 
one way and high the other. When opening a twisted 
saw in the center, as described, it is done with the round 
pien of the hammer. The long pien is not to be used on 
the saw, while on the anvil, always the round pien on the 
anvil. Twisted saws do not have the twist all on one side, 
but generally about as many buckles on one side as on the 
other and nearly always on opposite sides of the saw, as at 
^ and S, Fig. III. Straightening a twisted saw is some- 
thing that puzzles half of the professional saw hammers, 
from the fact that they do not know the principles upon 
which to treat a saw. Some instructors in hammering 
claim to remove a twist on the block is the proper way j 
one way this will work, but if a saw is too long on the rim, a 
man may hammer a life time on the block and never im- 
prove the twist. Eemember this, always treat a twisted 
saw exactly as Fig. III^ until you get the center a little 
open so that putting your fingers in the eye of the saw, 
while standing, you can move it a little easily, then you 
can go to the block and straighten your twisted saw, if you 
have one after doing this. 



[18] 

PART 6. 



SHOWING UNEQUAL TENSION IN A SAW WHEN IT IS 
TENSIONED TO PROPER SPEED. 

I 




FIGS^UR^E A I. 

Figiir.^ shows a saw with unequal tension in it, that 
is one part of the saw on a line of the circumference, is 
more open than the other, when the saw is open properlj- 
in the center to speed. Correcting this unequal tension is 
termed adjusting a saw properly. This may be called the 
finest and most complicated work of the Avhole saw, and 
is the finishing touch. Such work as this has never entered 
the mind of many saw hammerers, and I have seen many 
experts fail to hammer a high speeded thin saw to run 
just from this cause. They look at it as many do, that 
if a saw is opened i)roperly in the center true, and in good 



[19] 

cutting order, it should go all right, but not so. Now 
unequal tension is this, one part of the saw at the same 
distance from the rim or center, on a line of the circum- 
ference, is more open than another, one i)lace being to the 
extreme too open, the other being to the extreme too tight. 
This is caused pricipally from the fogy way of hammering 
a saw on the anvil for everything, and as the lumps in a 
saw are about as uniform, as shown in Fig, IIj there is 
reason why a saw should soon become unequally tensioned 
by this promiscuous hammering on the anvil. Uniform 
hammering does not always keep up equal tension, as in 
Fi(j. Illy one place in a saw may be a little higher temper 
and another a little softer, so from the same heft of blows 
the soft place is all the time opening more than the hard 
place. Uniform hammering is always the saftest, as the 
promiscuous hammering is sure to always keep a saw in a 
bad condition. To find unequal tension the saw must be 
gotten as true as possible on the block. Then put it on 
the bench and set out screws I) D until you have the saw 
dished toward jou preceptibly, then take the long straight 
edge in your left hand, turn the saw Avitb your right. Turn 
the saw a few revolutions and watch very closely the 
openings under the straight edge and wherever the saw 
appears more open make a loop mark as at ^^ Fig. VI 
and where it shows leys light, the straight edge fitting 
closer, make a long mark, watch very closely and have the 
very best light and mark the least preceptible difference in 
the light while revolving the saw, if any of the openings 
seem to be nearer the center mark them nearer as at S, 
Now take the saw otf the bench and turn it around, the 
other side to you, not disturbing screws D B. Now apply 
the straight edge opposite each one of the loop marks 
and if the straight edge stands off and does not show a 
high place, this is an indication of a loose place in the saw, 
the saw being too open there. Turn the saw to the straight 



[20] 



marks and notice if the straight edge shows less light than 
what it did opposite the loop mark, if so it is a tight place 
in the saw. Loose places stand off from the straight edge 
on both sides of the saw, tight places do not, the saw has 
the appearance of being thicker there. In testing for un- 
equal tension, great care should be used, and where the 
saw stands off on one side from the straight edge and 
shows a lump or high place on the other, this is an 
indication of a lump and should be straightened on the 
block. Unequal tension is always alike on both sides of 
the saw. One side may stand off a fraction more than the 
other, if the saw is not straightened up well before testing 
for unequal tension. By watching closely it will soon be 
learned, the screws J) J) being the best guide of all, they 
hold the saw firm, dished the same all the way around, 
where the saw is si)rung or dished by the hand it is im[)os- 
sible to spring the saw alike all around and so uneciual 
tension is found where there is none. None but the very 
best hammerers can trust to springing a saw and should 
they have a rig of this kind it would be better. After 
finding all the unequal tension in the saw, it will then be 
necessary to remove it by hammering on the auvil. The 
open i)laces where the straight edge stiinds off, should be 
opened on the rim, as at 2 and S, FiQ. VI. This expands 
the rim, making the center tight. Where a tight place is 
found the straight e Ige showing a high place on both 
sides of the saw it should be hammered, as at 2 this 
stretches the saw near the center, opens it and makes the 
rim tight. Where the saw is tight near the center it is 
loose on the rim, and where it is loose in the center it is 
tight on the rim. Many do not believe this, but they can 
find it out by testing the saw. All you have to look after 
in testing for unequal tension, is between center and rim, 
with straight edge in perpendicular position. Watch the 
openings and tight places closely, they sometimes appear 



[21] 

nearer the rim, as at 2 aud nearer the center, as at ^. 
Strike about as many blows, as in cut, very ligbtly on tbe 
anvil with tbe round pien on botb sides of tbe saw, and 
tbis will do for tbis time, as you may bave tbe saw sprung 
some and so you can't test furtber, straigbten up tbe saw 
on tbe block and you will bave anotber better running saw. 
Tbe next time you hammer your saw examine again for 
unequal tension and you will keep a perfect saw, which 
will stand up to nearly twice tbe feed and making smootbe 
true lumber. In the low speed and thick saws, tbis unequal 
tension does not show up so much in tbe runniug of the 
saw. But tbis advanced day is laying aside tbe slow low 
speed. 



PART 7. 



LONG MILL AND CllOSS OUT t-'AWS. 



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F'C 7 



t^IGMJI^E VII. 



[22] 

Straight saws require hardly auythiDg but straight- 
en iog oil tlie block the same treatment as the circular. 
If they are keyed up iu a gate as the gang saw they require 
more than straightening and require tensioning not to speed 
but to the strain in the gate, this strain should be on both 
edges of the saw and the center loose. This is done by 
hammering the center as at ^ on the anvil alike on both 
sides. To find the proper opening of the saw it should be 
put in a leaning position, so that the saw will sag, then 
apply the straight edge across the saw, if it is too tight in 
the center and loose or long on the edges the center will 
appear a little high and to turn the saw over it will appear 
the same on this side, and exactly the same as treating the 
circular for unequal tension. The straight edge should be 
api)lied all along the saw and mark all the high places, 
turn the saw over and test it, if any high marks appear 
opi)osite, this is a tight place, and where it is high on one 
side in the center and low on the other, it is a lump and 
should be tai<en to the block. If the saw appears very 
tight in the center, it will be best to hammer it on two 
lines, as at ^ and then test for unequal tension, which is as 
essential to a good running gang as in the circular. When 
your saw shows a little opening all the way the length of 
it on both sides while sagging it has about the jn'oper 
tension, always in testing for the tension never ai)i)ly the 
straight edge under the saw, but always turn it over test- 
ing it, saw sagging in the center always straightening ui> 
on the block. When a long saw is only to be straightened 
it is laid flat on a straight board and tested with the 
straight edge in this way. Long saws require the use of 
the long pien almost entirely in straightening. ,^ repre- 
sents a bent saw ; :j shows how it is laid oft" for the long 
pien, but saws requires the most straightening on the edge 
and when you straighten the two edges the center will be 
nearly straight. S should be straightened at A-B on the 



[23 J 

edge with the long pieu until nearly straight, then if the cen- 
ter has any high xilaces, work on them. 2 shows a twisted 
saw, cross cut is straightened the same as the gang on 
the block, sometimes the tooth edge, from press gumming 
and heating with the emery wheel, Avill get the saw so long 
on that edge, that it will assume a twist on this edge, 
while the back remains straight, when this is the case, 
hammer the saw on the anvil as at ^^ but lay off another 
line on the back eA^Q^ having 3 lines in all, work on both 
sides and then you can straighten your saw. This trouble 
seldom happens and when it does, it is in broad drag saws. 
All drag saws require to be the same tension across the 
saw, the center and edge the same strain. Cross cut saws 
require only straightening. The mooley the same as the 
drag, the hand saw the same as the cross cut, remembeiing 
that all long saws are much thinner than circulars and 
require lighter blows. 



PART 8. 

SHINGLE AND SMALL CIRCULAR SAWS. 

Shingle saws seldom require anything but to be kept 
straight, the collar extending so near the rim that it is not 
affected much by centrifugal force. Sometimes shingle 
saws become bent by a spalt catching under the carriage 
in this case, the saw can nearlj^ always be straightened 
without being taken off the collar, it being best not to take 
it off', unless compelled to and then you must use double 
I)recaution or you will never get it any better. These saws 
nearly always get sprung on the rim and require the use 
of the long pien more than the round and only a very 
light tap being necessary, as shingle saws are very thin on 
the edge. Sometimes a saw will appear out of true, making 
a rough shingle. When the saw is found not to be sprung 
with the straight edge and runs out of true, the collar 



[24J 

* 

is sprung, it being cast iron, and heat froui* the journal is 
liable to spring or warp it, so liere you can't -do any liam- 
mering, but must loosen the screws in collar opposite the 
low places in the rim, slip in one or two thicknesses of paper 
until you get tlie saw practically true, this being the only 
remedy, unless the collar was taken to a machine shop 
turned and ballanced. Shingle saws should be left a little 
high on the rim, the center, the lowest showing good light 
under tlie straight edge. Small circulars are always 
straightened on the block, unless the edge has become 
so long by gumming to form a twisted saw, then it will 
require hammering on the anvil, as in FUj. III. It should 
be opeiu'd in this wny before it gets so loose as to twist, 
this can be seen by watching the saw at work, it appearing 
wavy 0:1 the rim. 



PART 9 



THINGS TO KEEP ALWAYS IN VIEW IN FOLLOAVING THE 
INSTRUCTIONS OF THIS BOOK. 

1st. No saw is to be treated for lumps except on the 
block. 

2d. In all adjustment to speed, the blows are applied 
uniformly on the anvil with the round pien. 

3d. All straightening applies only to the block, 

4tli. All hammering applies to the anvil only. 

5th. Correcting unequal tension applies only to the 
anvil. 

Otli. The round pien being only used on the anvil, 
the round and long being used on the block. 

7th. Always a])ply the straight edge both ways at 
right nngles on the saw. It may appear straighter one 
way than the other, and is the only way to find twists in a 
saw. 

8th. All twisted places are treated on the block witli 
the long pien in line with the straightest way of the saw. 
Twisted saws are sometimes so long on the rim as to torm 
a twist, treat them as described. 

9th. Do not attempt any part of this book without 
studying it thoroughly, as this is necessary to your success. 



LIBRARY OF CONGRESS 




